Hauptrotor

Hauptrotor, or main rotor, is the primary lifting rotor of a helicopter. It is a set of rotor blades mounted to a central hub on a mast, driven by the aircraft’s engine or turbine via a main shaft and transmission. As the rotor spins, each blade acts as a lifting surface, producing thrust perpendicular to the rotor plane. The combined lift supports the aircraft in flight, while cyclic and collective controls modulate the rotor’s pitch to control attitude and altitude. The cyclic control tilts the rotor disk to produce lateral and longitudinal movement, while the collective changes the blade pitch uniformly to raise or lower lift.

Helicopters use a tail rotor or alternative anti-torque system to counteract the engine torque applied to the Hauptrotor. The main rotor’s speed is typically maintained around a fixed value by the transmission, and pilots adjust thrust and airspeed by changing blade pitch and rotor speed as appropriate. Modern rotor systems may be rigid, semirigid, or fully articulated, and commonly feature two to four blades. Blade materials range from metal to composites, and hubs may be articulated to allow flapping, lead-lag motion, and pitch changes.

Maintenance includes regular inspection of blades for damage or delamination, balancing and tracking the rotor, and checking the hub and transmission for wear. Proper synchronization of inputs to the swashplate is essential to avoid excessive vibration. The term Hauptrotor is used primarily in German-language aviation literature to denote the main rotor, distinct from secondary rotors such as the tail rotor or auxiliary rotors.